US Patent 9215581 Distance-based presence management

Various operations may be performed based on a distance-related function associated with two or more devices. For example, an association procedure for two or more devices may be based on one or more determined distances. Similarly, presence management may be based on one or more determined distances. A distance-related function may take various form including, for example, a distance between devices, two or more distances between devices, a rate of change in a relative distance between devices, relative acceleration between devices, or some combination of two or more of the these distance-related functions.